Shrink wrap apparatus



NOV. 12, 1968 GOTTILY ET AL 3,410,048

SHRINK WRAP APPARATUS 2 Sheets-Sheet 1 Filed May 25, 1965 INVENTORSARTHUR L. GOTTILY JOHN L.THOMAS BY am .2630

AGENT NOV. 12, 1968 GQTTILY ET AL 3,410,048

SHRINK WRAP APPARATUS 2 Sheets-Sheet 2 Filed May 25. 1965 INVENTORSARTHUR L. GOTTILY JOHN L. THOMAS AGENT United States Patent Office3,410,048 Patented Nov. 12, 1968 3,410,048 SHRINK WRAP APPARATUS ArthurL. Gottily and John L. Thomas, Pensacola, Fla.,

assrgnors to Monsanto Company, St. Louis, Mo., a corporation of DelawareFiled May 25, 1965, Ser. No. 458,679 11 Claims. (Cl. 53-77) ABSTRACT OFTHE DISCLOSURE Shrink wrapping or bagging apparatus including athermally controlled oven and a reciprocating carrier adapted to carryitems covered with shrink wrap material into and out of the oven.

A conventional shrink wrap packaging machine, in general, comprises ahorizontally moving endless conveyor and an oven positioned over theconveyor. Merchandise wrapped in thermoplastic shrink material is placedon the conveyor and is carried through the thermally controlled oven.Some disadvantages are apparent when conventional conveyor type machinesare used to shrink wrappers for bags or bobbins packaged with yarn. Theyarn packages, usually precision wound and containing high quality yarn,are often damaged by the handling required and the apparatus used. Thebobbins must be laid on their sides on rollers or belts of the conveyorwhereby the tightly wound yarn wraps of the packages sometimes becomeloose and the packages lose their symmetry. Also, shrinkage of coversupon a package is not always uniform because a portion of the cover isalways in contact with the conveyor or belt and, therefore, is notexposed to the same thermal condition as the rest of the cover whenmoving through the oven. Another disadvantage is that conventionalapparatus is not compact, requires several operators, and occupies alarge amount of floor space.

It is an object of this invention to provide an upright reciprocatingtextile shrink wrap apparatus with safety features.

Another object of this invention is to provide shrink wrap or bagapparatus for wrapping goods with shrinkable thermoplastic materials.

Another object is to provide upright cabinet shrink wrap apparatus.

A further object is to provide a textile shrink Wrap machine adapted toautomatically deliver a plurality of bobbins packaged with yarn andcovered with shrinkable material into a thermal zone and to remove thebobbins therefrom after a controlled period.

The novel shrink wrap apparatus, in brief, comprises a thermallycontrolled'oven means and an automatic reciprocable bobbin carryingmeans adapted to carry a plurality of bobbins covered with thermoplasticshrink material into the oven for a pre-set controlled time forshrinking the material about the bobbins and to subsequently remove thebobbins therefrom.

A better understanding of the apparatus of the invention will be gainedby reference to the following more detailed description and to theattached drawings. In the drawings,

FIGURE 1 is a side elevation view of the novel shrink wrap apparatuswith parts broken away to show the various components thereof;

FIGURE 2 is an isometric view of part of the bobbin lift means withparts broken away; and

FIGURE 3 is a front elevation view of the novel shrink wrap apparatuswith parts broken away to more clearly illustrate the componentsthereof.

In the several figures in the drawing the same reference numerals areused to identify like components.

Referring to the drawings, FIGURES 13, the novel shrink wrap machine 1embodying the invention illustrated in one form comprises a frameassembly 2 supporting a thermally controlled shrink oven assembly 3above an automatic bobbin reciprocating assembly 4. The oven assembly 3and the reciprocating assembly 4 are supported on the frame assembly 2to provide an upright cabinet presenting a front side with electricalcontrols conveniently located for an operator of the machine.

The shrink oven assembly 3 comprises a housing 5 having insulatablylined side, upper and lower walls defining an enclosed oven volume orspace. Within the oven space there are a plurality of plenum enclosures6 defining a plurality of plenum chamber 7. Plenum enclosures 6 are,preferably, separately divided units and are spaced from the side wallsof housing 5 and have a plurality of openings or slots 8 therein andadjustable louvers (not shown) adjustably secured to the enclosures 6adjacent slots 8 for controlling flow of heated air to the interiorthereof. Access to each of the plenum chambers 7 through the bottom wallof housing 5 is provided by respective pivotal doors 10 each hingedlyconnected to the bottom of the back side of housing 5 and swingableinwardly of the plenum chambers 7. Preferably, each door 10 has a wearplate at its exterior side thereof.

Above and spaced from the plenum enclosures 6 is a fixed horizontalshroud plate 12 with a central aperture 13. A fan 14 is coaxiallyaligned with and positioned adjacent aperture 13. Fan 14- is driven by ashaft 15 extending through housing 5 and connected to motor 16 mountedon housing 5 and connected to a source of energy.

Between and in spaced relation from shroud plate 12 and plenumenclosures 6, heat resistance wires 17 suitably mounted to housing 5 andconnected to a source of energy provide heating units. When fan 14 isrotating, air flows past the resistance wires, is heated, and flows insurroundment of and into the plenum chambers 7 through slots 8 of theplenum enclosures 6. A plate 18 depends in the manner of a curtain fromthe upper wall of housing 5 at the back side of the plenum enclosures 6and serves to direct air flowing from the plenum chambers 7 to a zoneabove the shroud plate 12. The climate within the oven is controlled bya thermostat 19.

The reciprocating lift assembly 3 comprises a pair of reciprocablespaced bars 20 having a plurality of roller assemblies 21 mounted inspaced distances along the length thereof. Roller assemblies 21 contact,ride on, and connect each bar 20 to a respective frame rail 22. Each bar20 has a plurality of spaced aligned spindles or pegs 23 extendingangular-1y, upwardly and outwardly therefrom and is positioned below arespective door 10. Pegs 23 are aligned in a vertical plane below acorresponding door 10. At the upper end of each bar 20, a series ofoff-set rollers 24 roll against and open and close door 10 when bar 20is actuated into and out of a plenum chamber 7. By arranging rollers 24one behind the other and off-setting their height with the highestplaced nearest the front of a door 10 the latter can be fully opened andclosed in a smooth operation.

The reciprocable bars 20 move up and down rails 22 by means of a chaindrive transmission 25. Transmission 25 include a motor 26 connected toan energy source and a drive gear 27 connected to the shaft of motor 26.A pair of driven gears 28 each connected to one end of a drive gearshaft 29 mesh with and are driven in opposite directions by drive gear27. Each driven gear shaft 29 at its end opposite the driven gear has asprocket 30 fixed thereto. Interposed in each driven gear shaft 29 is anelectromagnetic clutch 31. Electromagnetic clutches 31 are controlled byoff-on switches 32 and microswitches 33 and microswitch actuators 34located substantially at the top and bottom of each bar 20. Each drivengear shaft 29 has a brake clutch 35 of conventional type mounted thereonfor permitting shafts 29 to rotate in one direction only for brakingshaft 29.

Below and in the same vertical plane of each sprocket 30 there is acorresponding lower sprocket 36 rotatably mounted on frame assembly 2and a link chain 37 is mounted to travel around corresponding upper andlower sprockets 30 and 36.

Each bar 20 has a counterweight 38 connected thereto by means of a chainand movable over a pulley mounted on the frame 2 for stabilizingmovement of bar 20.

Adjacent the lower end of each bar 20 is a slotted cam plate 40 aflixedthereto and a cam roller 41 is positioned within the cam slot. Each camroller 41 has a pin 42 extending therefrom and pin 42 extends throughand connects with a pair of links of a corresponding chain 37.

The shrink wrap machine cabinet, preferably, has a table surface at thefront side thereof below the oven for the convenience of an operator.Several air jets 43 connected to a source of pressurized air areprovided near the table. In the illustrated embodiment, the jets 43 arelocated adjacent the open ends of supported folded thermoplastic bags 46and the air flowing from jets 43 inflates or expands and thus preparesthe bags 46 for an operator prior to bagging a bobbin 45.

In operation, the motor 16 switch, the motor 26 switch and the heater 17switch all located on a control panel 44 are actuated to the on positionfor driving fan 14, driving gear 27, and heating wires 17, respectively.The electromagnetic clutches 31 are not energized at start-up andtherefore both gears 28 will be driven but shafts 29 will bedisconnected therefrom.

The oven is readily heated to the preset temperature as controlled bythermostat 19. Fan 14 circulates air past resistance wires 17 and theheated air circulates around and into the plenum enclosures throughslots 8. The separate plenum chambers 7 provide independent stabilizedthermal zones. The heated air leaves the plenum chambers 7 through theback sides thereof, is deflected to the space above shroud plate 12 byplate 18, and is recirculated in the same path described.

For purposes of simplicity, the operation of one reciprocable bar 20will be expalined only; however, it will be understood that both bars 20may be operated simultaneously, separately or sequentially. The operatorthen loads a packaged bobbin 45 on each of the pegs 23 On bar 20.Bobbins 45 are hollow and easily mounted on the upwardly angled pegs 23.The operator next takes an expanded shrink bag 46 from a stack locatedabout the cabinet table and places the bag over the packaged bobbin 45mounted on a peg 23. Next, after loading bar 20 with bobbins andcovering them with shrink bags, the operator actuates off-on switches 32on the cabinet to close a circuit connected to a correspondingelectromagnetic clutch 31. The clutch 31, being energized, connectsshaft 29 to the shaft of motor 26 through gears 27 and 28 and chain 37is driven in a clockwise direction (FIG- URE 2). Since bar 20 isconnected to chain 37 through the cam roller 41, bar 20 is lifted into acorresponding plenum chamber 7. Door of the oven assembly 3 is pivotallyopened by the roller assembly 21. As bar moves into the plenum chamber7, the rollers of roll assembly 21 push door 10 wide open and bobbins 45are carried into the plenum chamber 7. When bar 20 reaches an upperlimit position with all of the bobbins 45 in the oven, a microswitchactuator 34 contacts a microswitch 33. The microswitch 33 is connectedto a delay circuit 48 such as a resistance capacitor and a relay networkor R-C circuit connected to the electromagnetic clutch 31 fordeenergizing clutch 31 and thereby discontinuing the movement of bar 20upward. Bar 20 is held in its upward limit position by the cam brakeclutch preventing rotation of shaft 29 in a counter-clockwise direction.Bobbins are kept in the oven for a pre-set dwell time by the delaycircuit while the bags are shrunk on the bobbins. The R-C circuit thenenergizes clutch 31 so that chain 37 is driven and bar 20 is loweredbringing the shrink wrapped bobbins out of the plenum chamber 7. Whenbar 20 reaches a predetermined lower position, another microswitchactuator 34 contacts a lower microswitch 33 mounted on the frame whichdenergizes clutch 31 to disconnect shaft 29 from the shaft of motor 26and to stop bar 20 in its lower or load position. The packaged andshrink wrapped bobbins are then removed and the machine 1 is ready for arepeat operation.

For safety reasons, if a bobbin is not mounted properly on a peg 23 andthe bobbin projects therefrom a distance such as to prevent its entranceinto the oven, photocells 50 are provided near the entrance to the ovento detect the unsafe condition and to break a circuit to theelectromagnetic clutch for stopping operation.

It will be noted that when motor 26 is operating, both gears 28 aredriven by gear 27, one in one direction and the other in the oppositedirection and that both bars 20 can carry a load of bobbins into theoven simultaneously, if desired, by actuating respective off-on switches32.

The novel upright shrink wrap machine is compact and offers a way ofshrink wrapping bobbins with a minimum of yarn package contact frommachine or handler.

It will be understood that variations and modifications of theillustrated embodiment are expected within the scope of the inventionand that limitations are only contemplated within the spirit of thefollowing claims.

We claim:

1. A textile shrink wrap apparatus comprising.

(a) an upright frame,

(b) a housing defining a plurality of oven plenum chambers and supportedtopside on said frame,

(c) means for thermally controlling said oven temperature,

(d) a plurality of movable closure means secured to said housing andproviding access through the bottom of said housing to each of saidplenum chambers,

(e) a plurality of reciprocable means mounted on said frame and adaptedto carry a plurality of bobbins wrapped in shrink material into and outof said plenum chambers and to open and close said movable closuremeans,

(f) means for actuating said reciprocable means,

(g) timing means for controlling said plurality of reciprocable means toprovide a predetermined dwell time of said bobbins in said plurality ofplenum chambers, and

(h) means for actuating said plurality of reciprocable means separatelyor in unison.

2. A textile shrink wrap apparatus as in claim 1 further comprisingsafety means for stopping reciprocation of any one of said plurality ofreciprocable means when unsafe conditions prevail.

3. Shrink wrap apparatus comprising in combination:

(a) means defining an oven having a single entranceexit opening thereto,

(b) means for heating said oven,

(c) means for supporting at least one article wrapped in shrink materialand for reciprocating the same into and out of said oven through saidsingle opening,

(d) movable cover means closing said opening, and

(e) means for controlling the opening and closing of said movable covermeans in cooperation with the reciprocating of said article into and outof said oven.

4. Shrink wrap apparatus as in claim 3, wherein said means forsupporting said article is adapted to axially support at least onetextile bobbin.

5. Shrink wrap apparatus as in claim 3, wherein said opening is at thebottom of said oven and said reciprocable means is vertically operable.

6. Shrink wrap apparatus as in claim 3, wherein said movable cover meansis a pivotal cover, and said means for controlling said pivotal cover iscarried on said reciprocable means.

7. Shrink wrap apparatus as in claim 3, comprising means for controllingsaid reciprocable means to provide a predetermined dwell time of said atleast one article in said oven.

8. Textile shrink wrap apparatus comprising in combination:

(a) means defining an oven having a plurality of plenum chambers eachhaving a single entrance-exit opening at the bottom side thereof,

(b) means for heating said oven,

(c) movable cover means closing each of said entranceexit openings,

((1) a plurality of reciprocating means each adapted to support at leastone textile bobbin and each being vertically reciprocable to carrytextile bobbins into and out of said plenum chambers through saidopenings,

(e) means for actuating said reciprocating means, and

(f) means for controlling the opening and closing of said movable covermeans in cooperation with the reciprocating of said textile bobbins intoand out of said plenum chambers.

9. Textile shrink wrap apparatus as in claim 8, comprising means foractuating said plurality of reciprocating means separately or in unison.

10. Textile shrink wrap apparatus comprising:

(a) an oven having an entrance-exit opening at the bottom side thereof,

(b) means for heating said oven,

(c) a pivotal closure means covering said opening,

(d) reciprocable means adapted to carry at least one textile bobbinWrapped in shrink material into and out of said oven and having meansfor cooperatively opening and closing said pivotal closure means, and

(e) means for actuating said reciprocable means.

11. Textile shrink wrap apparatus comprising in combination:

(a) an oven having a plurality of plenum chambers each having a singleentrance-exit opening at the bottom side thereof,

(b) means for heating said oven,

(0) movable cover means closing each of said entranceexit openings,

(d) a plurality of reciprocating means each adapted to support at leastone textile bobbin and each being vertically reciprocable to carrytextile bobbins into and out of said plenum chambers through saidopenings,

(e) means for actuating said reciprocating means, and

(f) means for controlling the opening and closing of said movable covermeans in cooperation with the reciprocating of said textile bobbins intoand out of said plenum chambers.

References Cited UNITED STATES PATENTS 1,904,580 4/1933 Van Nordstrand219388 30 TRAVIS S. MCGEHEE, Primary Examiner.

